Deep in the heart of the Atacama desert are figures of what appears to be "alien" life-forms which were cut into the desert varnish by native Americans, as pictured alongside.
Whilst it has been suggested that the desert varnish itself could be the result of ecological processes or could be caused by chemical reactions occurring over periods of thousands of years, there is currently no evidence whatsoever to prove that this may be the case.
Professor Carol Cleland of Colorado University has different ideas. Professor Cleland believes that the desert varnish is more likely to be the result of some kind of life which exists in the ethereal plane and is therefore not perceptible to us. Professor Cleleand calls this ethereal dimension the "shadow biosphere" which could be full of invisible life-forms that are co-habiting Earth with us.
Professor Clelands ideas were published in peer reviewed journal, International Journal of Astrobiology, in 2006 in which she argued that we only currently use methods to detect micro-organisms based on our own biochemistry and that, if shadow microbes do indeed exist, we are therefore incapable of detecting them anyway.
In her report, Professor Cleland stated:
"On Earth we may be co-inhabiting with microbial lifeforms that have
a completely different biochemistry from the one shared by life as we
currently know it."
Numerous other astrobiologists also support Professor Cleland's claims, including Chris McKay of NASA's Ames Research Center, California and
Paul Davies, who published a similar paper to Cleland's in 2005 in peer reviewed journal, Astrobiology
Professor Cleland also explains:
"All the micro-organisms we have detected on Earth to date have had a biology
like our own: proteins made up of a maximum of 20 amino acids and a DNA
genetic code made out of only four chemical bases: adenine, cytosine,
guanine and thymine, yet there are up to 100 amino acids in nature and
at least a dozen bases. These could easily have combined in the remote
past to create lifeforms with a very different biochemistry to our own.
More to the point, some may still exist in corners of the planet."
Dimitar Sasselov, Professor of Astronomy at Harvard University and Director of the Harvard Origins Of Life Initiative has also supported Professor Cleland's claims by stating:
"There is plenty of room for a shadow biosphere. That is clear.
Certainly, it is not true, as some allege, that we have strong evidence
to show that it does not exist. In fact, the opposite is true: we do not
have good enough evidence to dismiss it."
Professor Sasselov also explained how levels of carbon dioxide in Earth's atmosphere cannot be accounted for by the life we know of on Earth by stating:
"If you want a clue you can count up the amount of carbon that is
emitted by living things – cows, sheep, grass, plants, forests and all
the planet's bacteria. When you do, you find there is a discrepancy of
around 5% when you compare the amount given off from Earth's standard
biosphere and the amount you find in the atmosphere."
[ Image: BWAC Images/Alamy - Public Domain ]